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    \node (E) at (0,0) {E}
    [level distance=2.5em,sibling distance=3em]
    child  {node (1T) {T} 
        child {node (2T) {T} 
            child {node (3F) {F}
                child {node (4l) {(}}
                child {node (4E) {E}
                    child {node (5E) {E}
                        child {node (6T) {T}
                            child {node (7T) {T}}
                            child {node (7/) {/}}
                            child {node (7F) {F}}
                        }
                    }
                    child {node (5+) {+}}
                    child {node (5T) {T}
                        child {node (6F) {F}}
                    }
                }
                child {node (4r) {)}}
            }
        }
        child {node (2*) {*}}
        child {node (2F) {F} 
            child {node (3i) {i}}
        }
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    \node[anchor=west, align=left] (子树) at ([xshift=7em,yshift=-5.5em]E) {子树：以任何\\具有分支的结\\点为根所形成\\的树，称为原\\树的子树。};
    \node[anchor=west] (dot1) at ([xshift=-1em,yshift=-1em]子树.north west) {·};
    
    \node[anchor=west, align=left] (简单子树) at ([yshift=-10em]子树.west) {\textcolor{red}{简单子树}：仅\\具有单层分支\\的子树};
    \node[anchor=west, text=red] (dot2) at ([xshift=-1em,yshift=-1em]简单子树.north west) {·};
    
    
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